The present invention relates to rotary sprinklers, and particularly to the ball-type rotary sprinkler in which the sprinkler is rotated in a series of stepped increments by impacting a ball against an abutment carried by the sprinkler.
The conventional ball-type rotary sprinkler includes a swirl chamber containing at least one ball which is driven around the chamber by the water flowing from the sprinkler inlet to the sprinkler outlet to produce the impacts rotating the sprinkler. Since, in such a sprinkler, the ball is in the flow path of the water, the ball imposes a resistance to the flow of the water through the sprinkler; moreover, dirt within the water may settle in the swirl chamber and/or on the ball, thereby making the sprinkler susceptible to jamming.